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•
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Figure 3
Distinctive mass fragments ensure positive identification
of lidocaine and caffeine.
Figure 4
Pinnacle II™ Amino column provides fast, reliable analyses
for sugars.
positive identification and allowed quantification of
each compound. Lidocaine and caffeine have dis-
tinctive mass fragments of 86m/z and 194m/z,
respectively (Figure 3).
HPLC
Sugars are not easily volatilized and, therefore, are
difficult to analyze by GC, making HPLC the better
chromatographic approach for this analysis.
Further, refractive index (RI) or evaporative light-
scattering (ELS) detection must be used because
sugars have no UV chromophore. HPLC/RI or
HPLC/ELS provides reproducible retention times,
adequate peak identification and good quantifica-
tion for sugars, as shown in Figure 4.
HPLC/MS methods for simultaneous analysis of
cocaine, sugars, and other classes of adulterants and
diluents have not yet been developed, but such
methods would enable analysts to evaluate street
cocaine mixtures in one analysis. Column parame-
ters and mobile phase composition will be critical
parameters to optimize.
Conclusions
Cocaine samples can be “fingerprinted” by identify-
ing and quantifying the adulterants and diluents
mixed with the drug. GC/MS provides adequate
quantitative information about the concentration
of each additive, relative to the cocaine concentra-
tion, and provides undisputable identification of a
substance (retention time andmass spectrumdata).
Therefore, GC/MS is the preferred chromatograph-
ic method for analyzing cocaine and most cocaine
adulterants. Sugars are best analyzed by HPLC.
for more information
Smith, F.P,
Handbook of Forensic Drug Analysis
, pp.235-275,
Elsevier, 2005.
Telepchak, M.J., T.F. August, and G. Chaney,
Forensic and Clinical
Applications of Solid Phase Extraction
, pp.204-213, Humana
Press, 2004.
Pinnacle II™ Amino
3µm Particles, 4.6mm ID
cat. #
price
150mm
9217365
$284
Rtx®-440 (fused silica)
(proprietary intermediate-polarity Crossbond
®
phase)
ID df (µm)
temp. limits
length cat. #
price
0.25mm 0.25 20°C to 320/340°C 30-Meter 12923
$445
0.25mm 0.50 20°C to 320/340°C 30-Meter 12938
$445
Peak List:
Conc. (mg/mL)
1. fructose
2.0
2. glucose
2.1
3. sucrose
4.0
4. maltose
4.5
5. lactose
4.4
LC_0223
Column:
Pinnacle II
™
Amino
Cat. #:
9217365
Dimensions:
150 x 4.6mm
Particle size:
3µm
Pore size:
110Å
Conditions:
Mobile phase: water:acetonitrile (25:75, v/v)
Flow:
1.5 mL/min.
Temp.:
35°C
Det.:
refractive index @ 35°C
Sample:
Inj.:
5µL
Solvent:
mobile phase
glucose
2.0mg
fructose
2.1
lactose
4.4
maltose
4.5
sucrose
4.0
No data pack available.
Carbohydrate HPLC Performance Check Mix
Dry components in 4mL screw-cap vial.
Reconstitute in 1mL acetonitrile:water (75:25) to 2.0, 2.1, 4.4, 4.5,
4.0 mg/mL, respectively.
cat. # 31809 (ea.)
$30
tech
tip
We recommend using an HPLC guard column for this application.
For Trident
™
guard column systems, refer to our catalog, or visit
our website at
www.restek.com/hplc.Column:
Rtx
®
-440 30m, 0.25mm ID, 0.50µm (cat.# 12938)
Sample:
100µg/mL each compound in methanol
Inj.:
1.0µL split (split ratio 1:10), laminar cup splitter inlet liner (cat.# 20801)
Inj. temp.:
250°C
Carrier gas:
helium, constant flow
Flow rate:
1mL/min.
Oven temp.:
150°C to 275°C @ 25°C/min., to 300°C @ 15°C/min. (hold 5.0 min.)
Det.:
MS
Transfer line temp.: 180°C
Scan range:
35-550amu
Ionization:
EI
Mode:
scan
Lidocane
Caffeine